my 1995 legacy wagon has begun to misfire again this time it happens after the car has warmed up once its warm it starts missing when idling and will misfire while driving until i get some speed up then will stop missing until i slow down again or drive to easy for too long. i keep a code reader in the car 2 times today the check engine light began flashing and as soon as it would stop flashing and go solid i would scan it and get p0301 each time cylinder 1 misfire. i have new plugs on the car and i replaced the coil recently with another used coil. what do you think my issue is? witch cylinder is # 1?

original wires? can you shift the plug wires and swap with another cylinder?

Sounds like a spark related misfire.

What kind of plugs?

How old are the wires?

 

Cylinder one is front cylinder on the right side (passenger).

they are ngk platinum alloy plugs its what the parts store gave me for the car. the wires are the wires that were on the car when i bought it. the coil is a diamond coil that came from a junk yard car witch looked like it has the coil and wires replaced recently i should have grabbed the wires too. its been cold outside i haven't gone back out to the car since last night its still 9 degrees outside now. when i replaced the coil last time there was oil in the #1 spark plug hole could this oil be what is causing my misfire? it looked like it was running down the top of the block and into cylinder 1's spark plug hole. the oil was not pooled very high in the hole but it was there i cleaned it out when i changed the coil it could have pooled back in there again in this time now.

Edited January 8, 201511 yr by sirtokesalot

WOW its freekin cold out there. a quick look i pulled the spark plug boot and looked in with a flashlight. #1 spark plug is half way under oil. can this cause my misfire?

ok well i cleaned the oil out of there and put the plug back cars running now warming up. it missed for a moment when i first started it but im guessing that was from the little bit of oil that got in the cylinder because it cleared right up. once it warms up im going to take it for a drive to see if the problem is fixed and if it is than i need to figure out how the oil is getting in there.

well i drove it around for about 15 minutes without issues. it was idling for about 10 min before i left with it. it seems like its running fine now i tihnk the oil inside the spark plug hole was the cause of my misfire.

yes indeed it was.

 

happens more often on newer stuff that actually have spark plug tube seals.

 

is power steering fluid leaking down into the top/front of the engine?  that seems most likely, i'd check there.

honestly now that im really looking at it it looks and feels more like coolant than oil im going to clean that area and drive it and see where its coming from

Oil degrades the boot on the plug wire and allows spark to arc through it.

Fix the leak, then put a new set of plug wires on it.

 

Common leakers on top of the block in that area are the power steering pump, ad the oil pressure switch.

 

What color is your coolant? What color is the fluid that's getting in the plug well?

When you have the oil/fluid problem solved get high quality wires. Subaru OEM or some say NGK is good. And you really don't need platinum plugs--basic NGK "V-Power" plugs are just fine!